This invention relates to internal combustion engines having an exhaust gas converter with a secondary air-fuel supply.
U.S. Pat. No. 4,926,816 discloses a rotary piston engine having a secondary air supply selectively connectable to the combustion chamber exhaust port or to the exhaust gas converter. According to that patent, secondary air or an air-fuel mixture may be directed to the combustion chamber exhaust port at low engine speeds. At intermediate speeds, secondary air is directed to the exhaust gas converter, and at higher speeds no secondary air is supplied to either location.
German Offenlegungsschrift No. 39 35 612 discloses accumulators of the activated-carbon filter type for collecting fuel vapors formed in components of the fuel supply for an internal combustion engine, particularly the fuel tank or a carburetor, so as to prevent the vapors from escaping into the atmosphere. In view of the limited storage capacity of such fuel vapor accumulators, and to make use of the collected fuel vapors, regeneration of the filters takes place during operation of the internal combustion engine by connecting them to a suction line leading to the intake system of the engine. In this way, the accumulated fuel vapors are drawn into the combustion chambers of the engine and consumed in accordance with environmental regulations. Alternatively, as described in the same prior art document, air pumps driven by the engine may also be used for this purpose.